The transplant core (Core B) is crucial for all three projects in this proposal. The mission of this core is to provide the high quality rhesus macaques of appropriate age from one source at a reasonable cost and to provide a centralized expertise and service on germ cell transplantation of monkeys and mice and the related procedures. The services provided are as follows: (1) Co-ordinate the purchase, delivery and quarantine of specific pathogen free (SPF) rhesus monkeys for project 1 (Pittsburgh) Project 2 (Pittsburgh and MD Anderson) Project 3 (MD Anderson) from the MD Anderson primate breeding facility at Keeling center, Bastrop, TX; pay primate per diems; (2) Oversee the quarantining and pretesting of all the monkeys; (3) In coordination with the experimental design of each project, oversee or perform the procedures involved in the transplantation monkey testicular germ cells into the testis or grafting of testis tissues into the same (autologous) or another (allogeneic) rhesus monkey after cancer therapy. The procedures include the radiation or busulfan treatment, surgical collection of biopsies or whole testis and preparation of cell suspensions, cryopreservation of cells or tissues, preparation of cells for transplantation, treat monkeys receiving allogeneic transplantation with an immunosuppressive agent, and perform grafting or transplantation; (4) Co-ordinate the periodic collection of blood, semen, testicular biopsies, testis, or grafts for evaluation; (5) Purchase and pay per diems for all recipient mice used for primate to nude mouse xenotransplantation and mouse to mouse transplantation. (6) Perform transplants into mice in co-ordination with the experimental design of each project. All transplants of testis cells into monkeys or mice will be performed at the transplant core sites at MD Anderson Cancer Center or University of Pittsburgh. Core B manages all the monkeys dedicated for transplantation in the P01 and ensure regulatory compliance. The core includes veterinarians who will oversee or perform surgeries, anesthesia, post-surgical care and general care of NHPs. It is a cost-effective and efficient use of resources at the two centers.